2.1- ionic model

metal atoms lose electrons they form positive ions= cations

when non-metal atoms gain electrons they form negative ions called anions

to achieve a decrease in their potential energy, this lower energetic state is more stable

by atims attaining a full electron shell

which type of bonding occuring depending o the electronegativity of the atoms interacting with each other ionic= low electronegativtity atoms (metals) interacting with high electronegativity atoms (non-metals) covalent= both atoms have middle to high electroneagtivity (both non-metals) metallic= bot atoms have low electronegativity (both metals)

compare electronegativity difference between two atoms greater than 1.7 units=ionic less than 1.7 units=covalent

when the atoms in an ionic bonding achieve the same electronic configuration as a noble gas

electrostatic attractions between opositely charged ions

when ions have been formed the electrostatic force of attraction between oppositley charged ions causes them to pack together into a 3dimensinal giant ionic lattice with every cation surrounded by anions and vis versa

because the cation has formed through the loss of the outermost energy level (valence shell) because the anion has formed by the gain of electrons they are bigger than the neutral atom due to increase electron electron repulsion adn expansion of the outer energy level. In general the cation is smaller than anion

NH4+

SO4,2-

CO3,2-

NO3-

PO4, 3-

0H-

HCO3-

yes when molten or in solution, ions are free to move arund and can pass to the electrodes dipped in solution to become oxidised or reduced

yes, a large numer of ionic bonds must be broken to allow the ions to move around (a molten liquid_ or break free from the attractive forces completely (ionic gas)

yes, does not bend, once sufficient force is applied the structure gives away completely and the material snaps

more soluble in polar solvents that have an uneven charge distribution(such as water) thhan non-polar solvents (such as hexane) the ions become surrounded by the polar solvent molecules and are dissolve

by its lattice enthalpy which is the energy recquired to break up a mole of an ionic lattice into gaseous ions under standard conditions

enthalpy change when one mole of solid ionic compound is seperated into its gaseous ions.

the stability of the ionic lattice 2 factors affect the stability: size of the ions= smaller ions more closely the ions can pack together and attract each other charge on the ion= the more charged is the ion the stronger is the electrostatic force of attraction between them